Session: 30-10 Component Design and Testing

Paper Number: 154158

Experimental Analysis of Advanced Turbine for Supercritical CO2 Power Cycle 

An advanced first stage high pressure turbine blade for a supercritical CO2 power cycle is tested in the Big Rig for Aerothermal Stationary Turbine Analysis (BRASTA) annular cascade at the Purdue Experimental Turbine Aerothermal Laboratory (PETAL) high pressure blow down facility alongside a baseline blade for comparison of aerodynamic performance. Both geometries are tested simultaneously using a novel off-axis rig design to allow for the blade geometries to be scaled up to achieve higher Reynolds numbers. The off-axis design necessitates the use of discrete sectors of airfoils, which are designed and additively manufactured in house using an mSLA printer. Printing the blades allows for unique routing of passage for blade surface static pressure taps that contour to the blade shape instead of requiring a straight line view from surface tap to egress, allowing all instrumentation for 15%, 50%, and 85% span to exist in the same passage. A flow conditioning gauze is placed upstream of the blade passages to impart pressure, Mach, and swirl profiles to mimic the rotor relative frame inlet conditions to the blade. Downstream, a sonic valve is used to alter the backpressure to achieve different pressure ratios, and multiple blowdowns are performed at each setpoint. Performance data is obtained from inlet total pressure and temperature rakes, blade static pressure taps, and exit total pressure rakes. Oil visualization is performed using a silicone oil mixture containing titanium dioxide and pigmented for contrast of the blade suction side surface with the hub and shroud endwalls. The viscosity of the oil is tuned so that the oil does not fully thin and blow away during the time of the test, and endoscopic cameras are placed in the rig for live monitoring and recording. The experimental data is compared to the computational study of the baseline and advanced blades, and a performance comparison is presented based on blade loading, pressure losses through the cascade, and behavior of the secondary flows.

Presenting Author: Logan Tuite Purdue University

Presenting Author Biography: Logan completed his PhD in Fall 2024 at the Purdue Experimental Turbine Aerothermal Facility working on the design of advanced turbine blades for supercritical CO2 applications

Authors:

Logan Tuite Purdue University
Michael Butzen Purdue University
Guillermo Paniagua Purdue University